<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
    </style>
    
</head>
<body>
   123
</body>
<script>
    // 向浏览器打印 456
    document.write("456");
       
    /* 向控制台打印 */
    console.log("你在电脑前看这段文字");

    // 弹窗
    alert("期待你脚踏祥云");

    // int a = 10;
    // String s = "hello";

    b = 123;
    c = "Hello";

</script>
</html>